This invention relates to a method of measuring the shape of an object by a light spot detecting sensor using the light, such as a laser beam, and more particularly to a method of measuring the shape of an object in a non-contacting manner, which is capable of simply measuring a manufacturing error of an object.
Owing to the recent, rapid development of the opto-electronics, a shape-measuring apparatus provided with a light spot detecting sensor utilizing a laser beam for the measurement of the shape of an object has been developed. An example of such an apparatus is described in, for example, "Techniques for Sensor", February 1983 issue, paragraph "Measurement of Shape of Object by Light Spot Detecting Sensor", PP60 to 64.
This type of apparatus is used mostly for measuring the shape of an object after the object has been manufactured, and comparing this shape with the designed shape thereof to discuss a manufacturing error. In order to carry out this comparison, it is necessary to grasp in advance the relative positional relation between the object coordinate system in which the design values are defined and the shape-measuring coordinate system of the apparatus.